A Study of the γ-ray and X-ray Radiations of BL Lac Objects

摘要

The X-ray and γ-ray flux densities of 18 γ-loud BL Lac objects as wellas their average spectral indices of X-ray wave band (1 keV) and 7-ray wave band(>100 MeV) are collected, and the correlations among the various quantities areexamined. The results indicate: (1) The X-ray flux density and the 7-ray fluxdensity exhibit rather strong correlations in all the states, high, low or mediate.(2) Between the mean spectral indices in X-ray and γ-ray wave bands there is acomparatively intense anti-correlation. (3) Between the average spectral indicesand the X-ray and 7- flux densities there is no evident correlation either in thehigh or the mediate state. (4) Between the average spectral index of 7-ray waveband and the flux density of X-rays in low state there is a rather strong anti-correlation. Between the mean spectral index of X-ray wave band and the 7-flux density in low state there also exists a weak correlation. The results of ouranalysis support the viewpoint that both the X-ray and 7-ray emissions of BLLac objects come from the synchrotron radiation and synchrotron self Compton(SSC) radiation with one and the same distribution of relativistic electrons.